How to create a heptagon or heptagram with 99.992% accuracy only using a ruler and compass

In case you ever run into a situation where you need to draw an accurate heptagram, and you only have a ruler and compass, this tutorial might be of help. Thanks to GeoGebra.org that made it possible to verify the accuracy using vector graphics. Some other nice reads:
- A tuning system that is not arbitrary: http://www.schillerinstitute.org/fid_91-96/fid_911_jbt_tune.html
- Funny characteristics on number sequences applying numerological counting:
http://www.youtube.com/watch?v=Fbyc9JW3vtk